Hydraulic jack



Ap 1933- s. J. IWIDENER I I HYDRAULIC JACK :s Shets-Sheet 1 Filed May- 11. 1932 v Invehtor Jill Ja ne);

divrizi y fl Home y April 13, 1 s. J. WIDENER I 1,903,887

HYDRAULI C JACK Filed May 11. 1932 3 Shee ts-Sheet 2 Inventor,

mabnez;

flltorney S. J. WIDENER HYDRAULIC ACK April 18, 1933.

.Filed May '11. 1952 a Shets-Sheet :5

r 0 l n e w I fl Home y Pasta-d Apr. is, 1933' UNITED STATES s'rmme a. wmmvaa, or-auousra, eaonen um-m w m 11, was. we 80. 010,005.

This invention relates'to a hydraulic jack, the general object of the invention being to provide an air driven jack formed of a, single I unit with means for moving the head of the jack against the member to be lifted by forcing liquid from a liquid chamber into the jack chamber by means of air pressure,and then applying the air pressure to a motor for causing t e motor to pump the liquid into {)he jack cylinder to lift the object or mem- Another object of the invention is to provide a conduit between thejack cylinder and the fluid cylinder containing a" manually operated valve, whereby by opening this valve, the fluid .will run from the jack cylinder into the reservoir or fluid cylinder and thus permit the ob'ect' or member to lower under the'action o gravity.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts to be hereinafter fully described, illustrated in the accompanying drawingszand specifically pointed out in the appended claim.

' In describing the invention in detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which Figure 1 is an elevation of the invention.

Fig. 2 is a top plan view thereof;

Fig. 3 is a vertical sectional view.

Fig. 4 is a section on line 44 of Fig. 3.

Fig. 5' is a horizontal sectional view showing the valve means for the motor.

Fig. 6 is a view showing the piston, its screyiv, and the stem of the motor piston separate In these views, the numeral l-i'ndicates an cylinder base formed integrally with the.

cylinder 2, which forms the jack cylinder.

The upper end of the cylinder'2 is open and an elongated piston 3 fits in the cylinder and has a head or shoe-4 at its up r end. A

piston ring 5 fits in a groove in t e lower end 1 of the piston .3, and is held in place by the threaded ring 6. A cup washer may besubstituted for the ring, if desired.

i A reservoir or fluidcylinder 7 is suitably or cylinder 8-at theends thereof. Th ith the slide valve 25 podtion as attached-to the cylinder 2 and a chamber or cylinder 8 is formed in the base 1, the lower end of which is closed by a plug'9 threaded in the base. f

A passage 10 leads fromthe lower part of i the reservoir 7 to a small cylinder forming passage 11 which connects the cylinder 2 with thecharnber 8. A spring actuated valve 12 opens away from the reservoir 7 and is locatedin the outer end of the passage 10 F and a downwardly closing valve 13 is located in the upper part of the passage 11. A rod 14 passes t rough the reservoir andcarriesapiston 15 which is slidably arranged on the'rod and is normally held in raised position by aspring 16 on'the rod. The top of the reservoir has a port' 17 therein adapted to receive an air fitting connected to any suitable source of air supply and as will be seen when air is introduced into the upper end of the reservoir thru this port, the piston 15 will be forced downwardly and the fluid, which may be oil,in the reservoir, will be forced by the valve 12 into the passage 10 and then into the passage 11 and up past the valve 13 into the bottom of the cylinder 2 to raise the piston 3 and thus lace the head 4 against the object or mem r to be raised. V

A double, piston 18 is located. in the chamher or cylinder 8 and has a stem 19 projecting into the passage 11. A cup washer 20 is connected to the upper end of the stem by a screw 21. A valve block 22 is fastened to a flat side of the base 1 and has a nip le Y 'l he 23 thereon for receiving an air fitting. block has a cylinder 24 formed therein in which is located the sliding valve. 25 having the three flanges 26 thereon which are arranged, one at each end and one at the center.

The block is also provided with the exhaust ports 27 and 28, one at each side of the nipple. The four passages 29, 30, 31 and '32 connect the cylinder orchamber 24 with the chamber or cylinder 8, the passages 31 and 32' communicating with the chamber 8 adjacent the center thereof and the pmages 29 and 30 communicating with the chamber the piston 18 will pass through the passage 30 around the second part of the Valve 25 and escape thru the port 28. This upwardmovement of the piston 18 and its stem 19 will force fluid from the passage 11 into the cylinder 2 and act to raise the piston 3 and.

the object with which the head 4 of the piston engages. As soon as the piston 18 uncovers the passage 31, compressed air from the bottom of the chamber 8 will flow through this passage 31 into the chamber or cylinder 24, at the left end of said chamber, and thus force the valve to the right so that air will then pass from the supply through the nipple around the second part of the valve 9 and then through the passage to the upper end of the chamber 8 to force the piston 18 downwardly.

The air in the lower part of the chamber 8 will pass through the passage 29 into the chamber 24 and escape through the passage 27. This downward movement of the piston 18 will draw more fluid from the reservoir into the passages 10 and 11. As soon as the downward movement of the piston 18 uncovers the inner end of the passage '32, air will flow from the upper part of the chamber 8 through said passage 32 to the right hand end of the valve 25 and thus force said valve to the left again and thus air will again 5 flow to the bottom of the chamber 8 to raise the iston 18 again.

T us the piston 18 and its stem 19 acts as a pump or motor for pumping the oil from the reservoir into the cylinder 2 to lift the piston 3 and the object engaged by the head of the piston.

When the object is tobe lowered, a manually operated valve 33 in a pipe 34 which connects the bottom or the cylinder 2 with the reservoir, is opened so that pressure of the piston 3 and the object will force the fluid from the cylinder 2 through the pipe 34 back into the reservoir 7.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts provided that such changes fall within the scope of the appended claim.

Having thus described my invention, what I claim as new is A device of the class described comprising a cylinder, a piston in the cylinder and passing through the upper end thereof, a reservoir, a. motor cylinder located below the first mentioned cylinder and a small cylinder connecting the ottom of the first cy inder with the motor cylinder, a conduit connecting the moses? small cylinder with the reservoir, a downwardly closing check valve in the upper end of the small cylinder above the connection with the conduit, a check valve in the conduit closing toward the reservoir, a motor piston in the motor cylinder having a stem extending into the small cylinder, means, including an automatic valve, for introducing compressed fluid into the motor cylinder to reciprocate the piston and its stem therein, means for placing the fluid in the reservoir under pressure to force some of the fluid into the first cylinder to raise the piston therein against an object to be lifted, after which the motor piston is reciprocated for lifting the main piston and the object, a valve controlled conduit between the lower end of the main cylinder and the reservoir and ermitting the fluid in the main cylinder to ilow back into the reservoir when the valve is opened, said means for placing the fluid in the reservoir under pressure comprising a piston in the reservoir, a guide member passing thru the reservoir for guiding the piston, and spring means for normally holding said piston in the reservoir in raised position, and means for forcing air into the upper end of the reservoir to lower the piston.

In testimony whereof'l aifix my signature.

STERLING J. 'WIDENER. 

